Off the top of my head: Why is "Juno" ripping this movie's main character?

I loved that there was conflict between the main character and her best friend. Both start out in a very similar place upon graduating from high school: nonplussed about being done with school, nonplussed about an uncertain future, and nonplussed about the feelings of others. But ever-so subtly the characters grow apart. The main character Enid makes friends with a hopeless man and begins to become even more entrenched in her go-nowhere life. Rebecca, however, very slowly throughout the movie advances. A job here, a rented apartment there, brighter clothes as the movie progresses. We aren't surprised when Rebecca gets mad at Enid and, despite Enid being the main character, we root against her because we see how stale she has become. Yes, her life slowly falls apart and she breaks down but the viewer cannot sympathize with her. We just think: "Duh! Don't do dumb things."

This brings me to the name of the movie. I don't know if the concept is addressed in the book, but I see Enid as living in a Ghost World. She exists, but is she really there? She makes no impact on anyone's life. Sure, she gets the hopeless man a girlfriend, but then completely negates that relationship with her meddling. He goes back to his life as before and she goes on alone. She even boards a mysterious bus to unknown places at the end.

This isn't the type of movie that one can take lightly. Yes, it has some very funny moments. It also has very sad and dark moments. Ultimately, it made me think about what my life amounts to. Am I an Enid, constantly under achieving and blaming everyone else for my lack of gusto? Or am I like Rebecca, finding a purpose and going for it? Am I like both? Yes...